Viscosimeter



April 11, 1939. D. c, CLINE VISCOSIME'I EH Filed July 24, 1956 2Sheets-Sheet 1 INVENTOR DELBERT C. CL NE ATTORNEY April 11, 1939.

2 Sheets-Sheet 2 Filed July 24, l936 I INVENTOR DELBERT 6. (LINEATTORNEY Patented Apr. 11,1939

VISCOSIMETER.

Delbert C. Cline, Akron, Ohio, assignor to The Firestone Tire & RubberCompany, Akron, Ohio, a corporation of Ohio Application July 24, 1936,Serial No. 92,315

3 Claims. (Cl. 265-11) This invention relates to viscosimeters such asare used for determining the relative viscosity of liquids or solutions,and more especially it relates to viscosimeters oi the type wherein agravity- 5 impelled body is dropped through a column of liquid. 1

The chief objects of the invention are, to provide an improvedviscosimeter that is universally applicable for testing the viscosity ofall liquids;

Q to provide an instrument of the character men tioned that is notaffected by temperature or temperature changes; that may be used withequal facility for the testing of hot or cold liquids; that isconsistently accurate, and wherein there 5 is no personal factor toaffect the results obtained; to provide such an instrument that may beused with equal facility for testing opaque and transparent liquids; toprovide simplicity of construction and ease of cleaning the testmaterial 10 from the instrument; to devise an instrument capable oftesting volatile liquids without undue evaporation; and to provide aninstrument wherein it is possible to make a series of tests, for thepurpose of checking results, with the same col- ,5 umn of liquid. Otherobjects will be manifest as the specification proceeds.

Of the accompanying drawings:

Figure 1 is a side elevation of a viscosimeter embodying the invention,in its preferred form;

Figure 2 is a wiring diagram of the electrical mechanism thereof;

Figure 3 is a plan view of the instrument shown in Figure 1;

Figure 4 is a vertical section, on a larger scale,

5 of one of the magnetic switches of the device;

Figure 5 is a section onthe line 5-5 of Figure 1; and

Figure 6 is a section on the line 66 of Figure 1.

Reierring to the drawings, I is a base plate that is supported uponthree short legs of which two legs, II, II, are adjustable so that thebase plate may be accurately positioned in a horizontal plane. Risingfrom opposite sides of the base plate l0, substantially mediallythereof, are

standards or brackets l2, l2 that support a tubular metal sleeve l3, thelatter having a collar I4 secured intermediate its ends, which collar isformed with radially extending trunnions l5, l5

0 that are swiveled in the upper ends of the respective standards l2.Secured to the sleeve l3 and collar I4 is a downwardly extendingquadrantit that is positioned closely behind one of the standards l2, and hasits arcuate portion formed with 5 a series of apertures l1, l1 arrangedconcentrically of the trunnions IS. The apertures H are spaced 5 orapart, and are registerable with an aperture (not shown) in the adjacentstandard, and a suitable stud I8 is provided for insertion into thealigned apertures for holding- 5 the sleeve I 3 in determinate angularposition. Immediately above the respective apertures I! are suitableindicia l9 that denote at what angle the sleeve I3 is disposed when aparticular aperture is engaged with the stud Hi, the indicia of the 1said particular aperture being visible through an aperture formed instandard l2 immediately above stud Ill. The arrangement is such that thesleeve l3 may be positioned at various angles from vertical andhorizontal. l5

Receivable within the metal sleeve I3 is a tube 22 in which the liquidto be tested is placed. Preferably the tube 22 is of glass to permiteasy and thorough cleaning, and the sleeve I3 may be cut away as at 23,23 so that the tube 22 will 20 be visible therethrough. The tube 22 fitsloosely within the sleeve, and is restrained against movement relativelyof the sleeve by means of a springpressed pad 24 that is carried by amanually operable stud 25 mounted in the sleeve-collar ll. 25 One end ofthe tube 22 is closed by a suitable cork or stopper 26, and said stopperabuts a pin 21 extending diametrically across the sleeve at one endthereof, which end is lowermost when the sleeve is disposed in otherthan horizontal to position. The other end of the tube 22 is closed by astopper 28 that includes means for retaining and releasing a body thatis to pass through the liquid in the tube. The stopper 28 comprises abody portion of rubber, wood, or other suitable material upon which ismounted a tubular metal sleeve 29 that extends beyond the inner end oithe said body portion, the inner or free end of sleeve 29 having alune-shaped web 30 thereacross. Telescopically mounted within the pro- 1jecting portion of sleeve 29 is a cup-shaped metal member 3|, the closedend of which is secured. to a stem 32 that extends axially through thebody portion of the stopper and is provided with a knob exteriorlythereof by means of which member 3| may be manually rotated. The openend of member 3| is formed with lune-shaped web 33, similar to web 30 ofsleeve 29. The cupshaped member 3| constitutes a receptacle for aspherical metal ball 34 that is to pass through the liquid in tube 22,said liquid being designated 35.

The stopper 28 is so mounted in the tube 22 that when the latter isdisposed in other than vertical position the web 30 or stopper-sleeve 20is disposed at the upper side of the sleeve. When the cup-shaped member3! is so angularly positioned that its web 33 is disposed diametricallyopposite said web 30, as shown in Figure 1, the space between said websis too small for the ball 34 to pass therebetween, with the result thatsaid ball is retained within its receptacle. When the latter is rotatedangularly by means of its stem 32, its web 33 approaches coincidencewith web of sleeve 29, and there is ample space for the ball to pass outof its receptacle, and to move by gravity toward the lower end of thetube 22.

The feature of the ball-releasing stopper described makes it possiblealways to release the ball at the same point in the tube, thus makingfor uniformity in the testing of various liquids and in makingsuccessive tests of the same liquid. Preferably the tube 22 is filledwith suflicient liquid to contact the ball while the latter is in thestopper-receptacle to the end that the ball, when released, will notgain momentum before entering the liquid. An additional function of thestopper is to seal the opening in tube 22 when used for testing volatileliquids or solutions of materials in volatile solvents, without undueevaporation of the materials.

Mounted upon the under side of the sleeve I3 at two determinately spacedapart points thereon are respective magnetic electrical switchesgenerally designated 31 and 38, which switches are identical so that adetail description of one will sufiice for both.

As is most clearly shown in Figure 4, the switch 38 comprises anelongate glass bulb or tube 40 that is closed at both ends and ismounted in an open metal clip 4!. The latter is amxed to a suitableshelf or support 42 that has one end secured to a pair of paralleldepending arms 43, 43 by means of a bolt 44 that extends throughrespective elongate slots 45 in said arms. The other end of support 42is secured to one end of a pair of parallel arms 45 by a bolt 41 thatextends through slots 48 in the respective arms, the other ends of arms46 being secured to the .arms 43 by a bolt 49 that extends through saidslots 45 in said arms. The support 42 is formed with longitudinallyextending slots 50 through which both bolts 44 and 41 extend. The arms43 are secured at their upper ends to a collar 5! that encircles thesleeve i3. The arrangement provides adjustability for the switch 38 bymeans of which it may be moved toward or away from sleeve l3 and at anangle thereto.

The bulb or tube 40 is formed at one end with a protuberance withinwhich is a small ball of mercury 53 that is retained therein in allpositions of the switch by its own surface tension. Extending into themercury 53 is an electrical conductor wire 54 that extendslongitudinally of the tube and projects exteriorly thereof, said wirebeing supported by the sealed end portion of the tube. A secondelectrical conductor wire 55 extends through and is supported by thesealed end of the tube 40. Mounted on the inner end of conductor 55 is avolute spring 56, the outermost convolution of which is extended towardthat end of the tube that carries the mercury ball 53, there being anangular electrical contact member 51 secured to the free end of saidspring, and also a small steel plate 58 that may be influenced bymagnetic force. The arrangement is such that under normal conditions thefree end of the spring 55 is in the position shown in broken lines inFigure 4, and the contact member 51 is out of contact with the mercuryball 53. The

inner end of conductor wire 55 also carries a guide wire 59 that has anend looped about the contact member 51 as shown for preventing lateralmovement of the latter. The switches 31, 38 are of standard constructionand no novelty is claimed for the switches per se.

For energizing each magnetic switch, respective arcuate permanentmagnets 6|, iii are mounted upon the sleeve I3 and secured to therespective collars 5i by suitable clips 52. The magnets 5i extend partlyaround the sleeve I3 so as to pass between the tube 22 and the switches31, 33, the wall of the sleeve being cut away between the magnets andtube as shown at 53, Figure 4. The magnets 5| are spaced a determinatedistance apart, and in practice the distance of 12 inches has been foundquite satisfactory. By means of the switch supports previouslydescribed, it is possible to position the switches 31, 33 properlywithin the magnetic fields of the respective magnets Gl, with the resultthat the member 58 on the free end of volute spring 56 on each switch isdrawn against the wall of the tube 40 on the side thereof adjacent themagnet, and the contact member 51 is moved into the mercury ball 53 asis shown in full lines in Figure 4, and thus makes electrical connectionbetween conductor wires 54, 55. Suitable terminal blocks 55, 55 ofdielectric material are mounted upon the sleeve i 3 and to these blocksextend the various conductors of the electrical wiring of theinstrument.

The arrangement described is such that when the ball 34 is released fromits receptacle and rolls by gravity down the tube 22 through the liquid35 therein, it passes in succession through the magnetic fields of themagnets iii and deflects the magnetic lines of force in said fields withthe result that switches 31, 38 are momentarily opened in succession.The lapsed time between the opening of switch 31 and the opening ofswitch 38 is a function of the viscosity of the liquid 35, andelectrically operated means is provided for automatically and accuratelymeasuring said elapsed time, which means is controlled by said switches.

For measuring the time interval between the closing of switches 31, 35,an electric clock 53 is provided, which clock may be mounted upon thebase plate ID as shown. The clock 55 is of known, standard constructionand is of the type that employs two hands of which one records secondsand the other records hundredths of a second. The clock comprises amotor that is constantly driven, and an electrically operated clutch forengaging and disengaging the motor with the mechanism for turning thehands. The clock also includes means for restoring both hands thereof tozero after each period of use.

In addition to the elements described, the operation of the instrumentrequires a conversion unit 10 comprising a step-down transformer and arectifier, preferably of the copper-oxide type, for normally energizingrelay H through the electrical circuit which includes a resistance 12.This latter resistance is inserted in the circuit for the Purpose ofdetermining the normal energize.- tion of the relay Ii. The purpose ofthis resistance is to correct for the variations in electricalcharacteristics of the conversion unit and relay II in order that apredetermined normal energization in relay H may be obtained. A suitablecondenser 13 of approximately 1 mid. capacity is connected across theswitch 33 to reduce the are at the contact. These latter elements are inthe electrical circuit of the instrument and may be mounted at anyconvenient place removed from the instrument.

As shown in the wiring diagram, Figure 2, the instrument is operatedfrom a power line 15 of 110 volts A. C. The conversion unit 18 isconnected to the power line 15 by conductor wires I8, and deliverselectrical current, through conductor wires 11, 18 at 6 volts D. 0.Conductor wire extends from the conversion unit 18 to one terminal ofrelay II, the magnetic switch 88 being in said conductor 11. Conductorwire 18 extends from transformer I8, through resistor 12, to the otherterminal of relay 1|. The relay 'Il comprises a switch of which themovable member 19 thereof is connected to conductor 11 by means ofconnection 80. When the relay H is enersized the switch-member "I8 is incontact with the terminal of a conductor wire 8| that extends to oneside of the clutch 82 of the clock 88, the other side of said clutchbeing connected to conductor 18 through the agency of conductor 88. Whenthe relay H is de-energized, as shown in the diagram, switch member 19is biased by a suitable spring against contact with the terminal of aconductor wire 84 that extends to one side of magnetic switch 31, theother side of said switch being connected to conductor I8 through theagency of connection 85. The motor 86 of the clock 88 is connected tothe power line 15 by means of conductor wires 81.

The diagram of Figure 2 shows the condition of the device when it is inreadiness for the making of a viscosity test. Switches 81, 88 are inseries and closed, relay 'II is de-energized, the motor of the clock 88is running, and the clutch 82 is open so that there is no movement ofthe hands of the clock. The taking of the test requires only thereleasing of the ball 84 from its position in the elevated region of thetube 22. As the ball moves downwardly in the tube it first passesthrough the magnetic -field of the upper magnet 8| and deflects thelines of force thereof so as to permit the opening of switch 81. Currentfrom the conversion unit then passes through relay 1| to energize thesame and to move its switch member out of contact with conductor 84 andinto contact with conductor 8|, with the result that the clutch 82 isenergized and closed and causing motor 88 to drive the timing mechanismof the clock 88. This condition obtains until the ball 84 passes throughthe magnetic field of the lower magnet 8|, said ball then causing arepetition of the phenomenon described and effecting the opening ofmagnetic switch 88. The result is to de-energise relay II and cause theseveral mechanisms to resume their original position as shown, theopening of clutch 82 disconnecting motor 88 from the timing mechanismand stopping the clock. The elapsed time between the opening of theswitch 81 and switch 88wiliberecordedonthefaceofthe clock.

This completes a cycle of operation, whichmay be repeated for thepurpose of checking results, if desired, it being understood that theclock is restored to zero setting between successive tests. The onlylimitation to the number of tests that may be made with the same columnof liquid is the distance between the stopper 28 and the nearestpermanent magnet 8|, since it will be apparent that no further tests canbe made after the accumulation of balls 84 in the bottom of the tubeextends into the magnetic field of said magnet.

Since the tube 22 is symmetrical in shape and open at both ends, it iseasily and quickly cleaned. The instrument-is applicable for use withliquids of a wide range of viscosities, it gives consistently accurateresults, and achieves the other objects set out in the foregoingstatement of objects.

Modification may be resorted to without departing from the spirit of theinvention or the scope of the appended claims.

What is claimed is:

1. In a viscosimeter, the combination of a receptacle for liquid, ametal ball movable by gravity through said liquid, a closure in theupper end of said receptacle, .ball supporting means in said closure,means exteriorly of the receptacle for releasing the ball from saidclosure, means for establishing magnetic fields at two spaced apartregions in the course of said ball, and means for measuring the timerequired for the ball to move from one magnetic field to the other.

2. In a viscosimeter, the combination of a receptacle for liquid, ametal ball movable by gravity through said liquid, a stopper inserted atthe top ofthe receptacle for preventing evaporation when a volatileliquid is to be tested, said stopper comprising a compartment forsupporting the ball in determinate position at the top of saidreceptacle, means extending through the stopper to the exterior thereoffor opening said compartment to release the ball, means for establishingmagnetic fields at two spaced apart regions in the course of said ball,and means for measuring the time required for the ball to move from onemagnetic field to the other.

3. In a viscosimeter, the combination of a tubular receptacle for liquidpositionable vertically or at an angle thereto, removable stoppers atthe respective ends of the tube, the stopper at the upper end thereofcomprising a compartment at its inner end, a metal ball mo'vable bygravity through the liquid and mountable in said compartment, meansextending axially through said upper stopper, to the top thereof, foropening the bottom of the compartment to release the ball therefrom, andmeans for measuring the time required for the ball to move between twodeterminate points as it falls through the liquid to the bottom of thetubular receptacle.

'1' comm

